THE “CRUCIATE” RETROGRADE FEMORAL NAIL. DEVELOPMENT OF A NOVEL INTERNAL FIXATION DEVICE FOR STABILISATION OF CONDYLAR AND SUPRA-CONDYLAR FRACTURES OF THE FEMUR.

Abstract

Purposes of study: To design and introduce into clinical practice a more effective fixation method for condylar and supracondylar fractures of the distal femur, which provides secure fixation and permits the use of a minimally invasive surgical technique.

Methods and results: We have designed a novel implant for secure internal fixation of condylar and supracondylar fractures of the distal femur.

This involves a retrograde intramedullary nail with a unique “cruciate” configuration of distal locking bolts which stabilise the fractured condyles in relation to the shaft.

The optimal geometrical configuration of the distal locking bolts has been developed using cadaver studies. Following finalisation of the design, mechanical bench testing of the implant and clinical trials have been completed according to a protocol agreed with the UK Medical Devices Agency.

So far 36 patients have been treated using the implant which has proved to be effective and easy to use. Much less soft tissue dissection is required than when using conventional blade plates or DHS, or even newer “percutaneous” plating methods.

Conclusions: Mechanical testing on simulated specimens of both segmental defects and intercondylar “T” fractures has shown that the retrograde “cruciate” nail compares favourably with fixation with a DHS screw/plate implant.

Following completion of clinical trials, the Medical Devices Agency has granted approval for general use of the implant. It is anticipated that this will greatly facilitate the management of distal femoral fractures particularly those involving intercondylar fracture patterns.